The human placenta secretes a growth hormone variant (placental growth hormone) in increasing amounts during pregnancy. Pituitary GH is suppressed during the latter half of pregnancy, because of negative feedback on pituitary somatotrophs by placental GH. Following parturition, placental GH falls rapidly with a resultant GH deficient state and probable increase in insulin sensitivity. The objective of this study is to determine whether or not insulin secretion is suppressed in normal women during this time period.